Welder, an attorney who now lives in Bonner Springs, served as a delegate for Sanders at the 2016 Democratic National Convention when he was a resident of Missouri. He also worked as a grassroots organizer for Sanders’ presidential campaign.

"Brent has spent his career as an organizer and labor lawyer defending workers’ rights against exactly the giant corporations and billionaires that are rigging our economy and corrupting our political process,” Sanders said in a statement released by Welder’s campaign Monday.

Unlimited Digital Access: Only $0.99 For Your First Month

Get full access to The Kansas City Star content across all your devices.

“In Congress he will fight for a fifteen-dollar minimum wage, ending crippling student loan debt with debt-free college, and Medicare for all. I’m supporting Brent because he is the bold progressive voice Kansas needs in Congress."

Welder has borrowed heavily from the former presidential candidate’s fiery rhetoric about class inequality as he’s mounted his campaign against U.S. Rep. Kevin Yoder, the incumbent Republican from Overland Park.

C.J. Grover, Yoder's spokesman, said in an email that regardless of who the Democrats nominate "the contrast between Kevin and his eventual Democrat opponent in this race will be crystal clear. Kevin is out fighting for solutions and bringing people together every day and his opponent's platform will be extremism and obstruction."

The email included a link to a petition that directed people to a fundraising page after they signed.

Welder’s campaign called the link a mistake and donated the money raised from the email to the deputies’ families in the face of condemnation from the Fraternal Order of Police and his fellow Democrats.

Welder spokesman Shawn Borich said in an email that there "is a real chance" Sanders will return to the state to campaign on Welder's behalf.

Zach Helder, the spokesman for Tom Niermann, one of Welder's Democratic rivals, noted that his candidate had obtained endorsements from local lawmakers and mayors. He said those endorsements matter more than Sanders.

"Tom's a teacher, so while he may not be pals with big names like Bernie Sanders, he's incredibly close to the people in this community," Helder said in an email.

Read Next

A federal judge blocked President Donald Trump from building key sections of his border wall with money secured under his declaration of a national emergency, delivering what may prove a temporary setback on one of his highest priorities.